ICG-carboxylic acid is a near-infrared (NIR) fluorescent probe. ICG is a fluorescent dye reagent used in medical diagnostics. ICG has an absorption peak at 800 nm, which can absorb near-infrared laser energy and release heat in stained tissues.

Physicochemical Properties

Molecular Formula	C45H50N2O5S
Molecular Weight	730.953911304474
Exact Mass	730.344
CAS #	181934-09-8
PubChem CID	145710953
Appearance	Brown to black solid powder
LogP	9.4
Hydrogen Bond Donor Count	1
Hydrogen Bond Acceptor Count	6
Rotatable Bond Count	14
Heavy Atom Count	53
Complexity	1530
Defined Atom Stereocenter Count	0
SMILES	S(CCCCN1C2C=CC3C=CC=CC=3C=2C(C)(C)/C/1=C/C=C/C=C/C=C/C1C(C)(C)C2C3C=CC=CC=3C=CC=2[N+]=1CCCCCC(=O)O)(=O)(=O)[O-]
InChi Key	HIBVKROMGIHYKL-UHFFFAOYSA-N
InChi Code	InChI=1S/C45H50N2O5S/c1-44(2)39(46(30-16-8-11-25-41(48)49)37-28-26-33-19-12-14-21-35(33)42(37)44)23-9-6-5-7-10-24-40-45(3,4)43-36-22-15-13-20-34(36)27-29-38(43)47(40)31-17-18-32-53(50,51)52/h5-7,9-10,12-15,19-24,26-29H,8,11,16-18,25,30-32H2,1-4H3,(H-,48,49,50,51,52)
Chemical Name	4-[(2Z)-2-[(2E,4E,6E)-7-[3-(5-carboxypentyl)-1,1-dimethylbenzo[e]indol-3-ium-2-yl]hepta-2,4,6-trienylidene]-1,1-dimethylbenzo[e]indol-3-yl]butane-1-sulfonate
HS Tariff Code	2934.99.9001
Storage	Powder-20°C 3 years 4°C 2 years In solvent -80°C 6 months -20°C 1 month Note: This product requires protection from light (avoid light exposure) during transportation and storage.
Shipping Condition	Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Biological Activity

ln Vitro	Because of its well-established fluorescent qualities, indocyanine green (ICG), a water-soluble chemical, is often and safely employed in medical diagnostics. It has been applied to the identification of important structures, such as intra-abdominal malignancies, during fluorescence-guided surgery [1].
References	[1]. Combined application of Indocyanine green (ICG) and laser lead to targeted tumor cell destruction. J Pediatr Surg. 2018;53(12):2475-2479. [2]. Spectral characteristics of voltage-sensitive indocyanine green fluorescence in the heart. Sci Rep. 2017;7(1):7983. Published 2017 Aug 11.

Solubility Data

Solubility (In Vitro)

DMSO : ~50 mg/mL (~68.40 mM)

Solubility (In Vivo)

Solubility in Formulation 1: 2.5 mg/mL (3.42 mM) in 10% DMSO + 40% PEG300 +5% Tween-80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), suspension solution; with sonication. For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 + to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL. Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.  (Please use freshly prepared in vivo formulations for optimal results.)

Preparing Stock Solutions		1 mg	5 mg	10 mg
	1 mM	1.3681 mL	6.8404 mL	13.6808 mL
	5 mM	0.2736 mL	1.3681 mL	2.7362 mL
	10 mM	0.1368 mL	0.6840 mL	1.3681 mL

*Note: Please select an appropriate solvent for the preparation of stock solution based on your experiment needs. For most products, DMSO can be used for preparing stock solutions (e.g. 5 mM, 10 mM, or 20 mM concentration); some products with high aqueous solubility may be dissolved in water directly. Solubility information is available at the above Solubility Data section. Once the stock solution is prepared, aliquot it to routine usage volumes and store at -20°C or -80°C. Avoid repeated freeze and thaw cycles.